Thursday, June 08, 2017

It rained today; heavy at times, but mostly a miserable, stubborn drizzle that lasted all-the-grey-day-long. And the temperature climbed to a whopping 65° F. Hmmph! Not exactly optimum conditions for bloom in the grapevines - which seems to be going quite slowly this year. Come back, California-sunshine.
The number of days that the grapevines are in bloom is dependent upon the weather. When conditions are favourable bloom can take about 8-10 days, (but it can take as long as two weeks under cool conditions like the Napa Valley is experiencing now). And, of course, the flower clusters on a grapevine will not all bloom at exactly the same time, so that spreads bloom out a bit. Still, I think bloom is more protracted this year. I have also noticed that there are more clusters per shoot and that the clusters seem to be a bit bigger than the past two years.
Do not be alarmed by this picture of detached grape flowers from one cluster of Cabernet Sauvignon at TWWIAGE (and hand-modeled by a coworker). Although it looks like a lot of dead material; anthers, calyptra, stamens, etc., it is quite normal. As few as 20 to 30 percent of the flowers on a cluster will develop into berries, most will fall from the
cluster during the initial stages of berry growth. Furthermore, a significant
number of flowers will drop from the cluster about 8 to 12
days after full bloom: a stage commonly known as shatter. Fruit set is not complete until after shatter. Phew! It's a jungle out there. Fruit, set, now!